/*-------------------------------------------------------------------------
 *
 * spgvalidate.c
 *      Opclass validator for SP-GiST.
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *            src/backend/access/spgist/spgvalidate.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres.h"

#include "access/amvalidate.h"
#include "access/htup_details.h"
#include "access/spgist_private.h"
#include "catalog/pg_amop.h"
#include "catalog/pg_amproc.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/regproc.h"
#include "utils/syscache.h"


/*
 * Validator for an SP-GiST opclass.
 *
 * Some of the checks done here cover the whole opfamily, and therefore are
 * redundant when checking each opclass in a family.  But they don't run long
 * enough to be much of a problem, so we accept the duplication rather than
 * complicate the amvalidate API.
 */
bool
spgvalidate(Oid opclassoid)
{// #lizard forgives
    bool        result = true;
    HeapTuple    classtup;
    Form_pg_opclass classform;
    Oid            opfamilyoid;
    Oid            opcintype;
    char       *opclassname;
    HeapTuple    familytup;
    Form_pg_opfamily familyform;
    char       *opfamilyname;
    CatCList   *proclist,
               *oprlist;
    List       *grouplist;
    OpFamilyOpFuncGroup *opclassgroup;
    int            i;
    ListCell   *lc;

    /* Fetch opclass information */
    classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
    if (!HeapTupleIsValid(classtup))
        elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
    classform = (Form_pg_opclass) GETSTRUCT(classtup);

    opfamilyoid = classform->opcfamily;
    opcintype = classform->opcintype;
    opclassname = NameStr(classform->opcname);

    /* Fetch opfamily information */
    familytup = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfamilyoid));
    if (!HeapTupleIsValid(familytup))
        elog(ERROR, "cache lookup failed for operator family %u", opfamilyoid);
    familyform = (Form_pg_opfamily) GETSTRUCT(familytup);

    opfamilyname = NameStr(familyform->opfname);

    /* Fetch all operators and support functions of the opfamily */
    oprlist = SearchSysCacheList1(AMOPSTRATEGY, ObjectIdGetDatum(opfamilyoid));
    proclist = SearchSysCacheList1(AMPROCNUM, ObjectIdGetDatum(opfamilyoid));

    /* Check individual support functions */
    for (i = 0; i < proclist->n_members; i++)
    {
        HeapTuple    proctup = &proclist->members[i]->tuple;
        Form_pg_amproc procform = (Form_pg_amproc) GETSTRUCT(proctup);
        bool        ok;

        /*
         * All SP-GiST support functions should be registered with matching
         * left/right types
         */
        if (procform->amproclefttype != procform->amprocrighttype)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains support procedure %s with different left and right input types",
                            opfamilyname, "spgist",
                            format_procedure(procform->amproc))));
            result = false;
        }

        /* Check procedure numbers and function signatures */
        switch (procform->amprocnum)
        {
            case SPGIST_CONFIG_PROC:
            case SPGIST_CHOOSE_PROC:
            case SPGIST_PICKSPLIT_PROC:
            case SPGIST_INNER_CONSISTENT_PROC:
                ok = check_amproc_signature(procform->amproc, VOIDOID, true,
                                            2, 2, INTERNALOID, INTERNALOID);
                break;
            case SPGIST_LEAF_CONSISTENT_PROC:
                ok = check_amproc_signature(procform->amproc, BOOLOID, true,
                                            2, 2, INTERNALOID, INTERNALOID);
                break;
            default:
                ereport(INFO,
                        (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                         errmsg("operator family \"%s\" of access method %s contains function %s with invalid support number %d",
                                opfamilyname, "spgist",
                                format_procedure(procform->amproc),
                                procform->amprocnum)));
                result = false;
                continue;        /* don't want additional message */
        }

        if (!ok)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains function %s with wrong signature for support number %d",
                            opfamilyname, "spgist",
                            format_procedure(procform->amproc),
                            procform->amprocnum)));
            result = false;
        }
    }

    /* Check individual operators */
    for (i = 0; i < oprlist->n_members; i++)
    {
        HeapTuple    oprtup = &oprlist->members[i]->tuple;
        Form_pg_amop oprform = (Form_pg_amop) GETSTRUCT(oprtup);

        /* TODO: Check that only allowed strategy numbers exist */
        if (oprform->amopstrategy < 1 || oprform->amopstrategy > 63)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains operator %s with invalid strategy number %d",
                            opfamilyname, "spgist",
                            format_operator(oprform->amopopr),
                            oprform->amopstrategy)));
            result = false;
        }

        /* spgist doesn't support ORDER BY operators */
        if (oprform->amoppurpose != AMOP_SEARCH ||
            OidIsValid(oprform->amopsortfamily))
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains invalid ORDER BY specification for operator %s",
                            opfamilyname, "spgist",
                            format_operator(oprform->amopopr))));
            result = false;
        }

        /* Check operator signature --- same for all spgist strategies */
        if (!check_amop_signature(oprform->amopopr, BOOLOID,
                                  oprform->amoplefttype,
                                  oprform->amoprighttype))
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s contains operator %s with wrong signature",
                            opfamilyname, "spgist",
                            format_operator(oprform->amopopr))));
            result = false;
        }
    }

    /* Now check for inconsistent groups of operators/functions */
    grouplist = identify_opfamily_groups(oprlist, proclist);
    opclassgroup = NULL;
    foreach(lc, grouplist)
    {
        OpFamilyOpFuncGroup *thisgroup = (OpFamilyOpFuncGroup *) lfirst(lc);

        /* Remember the group exactly matching the test opclass */
        if (thisgroup->lefttype == opcintype &&
            thisgroup->righttype == opcintype)
            opclassgroup = thisgroup;

        /*
         * Complain if there are any datatype pairs with functions but no
         * operators.  This is about the best we can do for now to detect
         * missing operators.
         */
        if (thisgroup->operatorset == 0)
        {
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s is missing operator(s) for types %s and %s",
                            opfamilyname, "spgist",
                            format_type_be(thisgroup->lefttype),
                            format_type_be(thisgroup->righttype))));
            result = false;
        }

        /*
         * Complain if we're missing functions for any datatype, remembering
         * that SP-GiST doesn't use cross-type support functions.
         */
        if (thisgroup->lefttype != thisgroup->righttype)
            continue;

        for (i = 1; i <= SPGISTNProc; i++)
        {
            if ((thisgroup->functionset & (((uint64) 1) << i)) != 0)
                continue;        /* got it */
            ereport(INFO,
                    (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                     errmsg("operator family \"%s\" of access method %s is missing support function %d for type %s",
                            opfamilyname, "spgist", i,
                            format_type_be(thisgroup->lefttype))));
            result = false;
        }
    }

    /* Check that the originally-named opclass is supported */
    /* (if group is there, we already checked it adequately above) */
    if (!opclassgroup)
    {
        ereport(INFO,
                (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
                 errmsg("operator class \"%s\" of access method %s is missing operator(s)",
                        opclassname, "spgist")));
        result = false;
    }

    ReleaseCatCacheList(proclist);
    ReleaseCatCacheList(oprlist);
    ReleaseSysCache(familytup);
    ReleaseSysCache(classtup);

    return result;
}
